This patent document relates to display screens and display devices.
Many image and video displays are designed to produce colored images using arrays of light-emitting pixels physically present or visually formed on a screen. Each pixel can include a set of colored sub-pixels that each emits visible light of a respective color (e.g., red, blue, and green). The color composition and brightness of each pixel in an image can be controlled by the respective brightness of each colored sub-pixel of that pixel.
A viewer or an image capturing device can perceive or capture the image as a whole when the light emitted by all sub-pixels on the display during an image frame arrives at the viewer's eyes or the light-sensing structures of the image capturing device. In a digital image capturing device (e.g., a digital still camera or video camera), the light-sensing structures include photo-sensors distributed in one or more periodic arrays, and each photo-sensor is capable of detect light signals received at its respective location. The output image produced by the digital image capturing device is a composite of the light signals detected by all of photo-sensors in the one or more periodic arrays during one image frame.
Moiré patterns are interference patterns (e.g., alternating light and dark fringes) created, for example, when the two grids having slightly different mesh shapes, sizes, and/or pitches are overlaid on each other, or when two identical grids are overlaid at an angle. Moiré patterns often occur in images produced by various digital imaging and computer-graphics techniques, for example, when scanning a halftone picture or ray tracing a checkered plane. Sometimes, Moiré patterns also occur in digital images that capture objects having periodic structures, such as a wire mesh, a striped or checkered shirt, a cage, and so on. Moiré patterns that are present in digital images are often artifacts produced due to the discrete and periodic image capturing or processing characteristics of the imaging capturing device. Techniques for reducing Moiré patterns that occur in various types of situations are desirable for improving image quality.